NOVEL ACIDIC ALPHA-AMYLASE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To solve a variety of problems in the conventional starch industry by providing an acidicα-amylase and liquefying starch under acidic and high- temperature conditions. SOLUTION: This acidicα-amylase has following properties: (1) substrate specificity: acting on starch to mainly produce malto-pentaose and malto- hexaose; (2) the optimal pH: about 4.0 (3) pH stability: it is stable in the pH range of 4.5-5.0 under heating at 90 deg.C for 15 minutes; (4) temperature stability: it is stable up to 80 deg.C, when it is kept at a pH of 4.5 for 15 minutes; (5) optimal temperature: about 80-90 deg.C; (6) molecular weight: about 55,000-60,000 according to the gel filtration technique; and isoelectric point: about 4.2.